Abstract: Agl-type ice nucleus aerosols used in weather modification could obtained from burning different Agl-acetone sohitions.Their ice nucleating properties are not the same with each other. The available contributions about the solution formulations and the cloud chamber test results for six kinds of aerosols are summarized in this paper . The applicable conditions of these aerosols are also discussed.
Abstract: In this paper, based on the 5°×5° grid point data of the monthly sea level pressure in the southern hemisphere from May 1972 to February 1990, the characters of spatial-temporal variations for the circumpolar depression and subtropical high in the southern hemisphere are analysed. It is found that the change of the circulation system in southern hemisphere is close associated with the variation of the area and position of subtropical high over the Northwest Pacific in midsummer. The teleconnectional relation gives the clu& to forecasting the position of the subtropical high ridge line in July and August.
Abstract: In this paper, the annual drought index during 1470-1979 in North China are calculated.It is shown that this region suffered from the most serious droughts which lasted the longest periods in the last 500 years. The annual precipitation and the precipitaion of May-September in this period were decreased at least by 10-50 percent than the normal precipitation in the same period. And it is shown that the frequent and serious natural colamity are the main factors affecting the stabilities of not only the social economy, but also the social politics.
Abstract: In this paper, the relation of the apple's sugariness, acidness and hardness with meteorological condition has been studied. It is shown that expansion and mature period are the key biological phases in which the meteorological conditions mainly affect the apple's quality.The meteorological indexes and mathematical simulation equations for apple's sugariness, acidness and hardness are given, too.